The main concentration of this work is to look at the forms and functions of morphological doubling in syntax and it aims at to look at the functions and roles of double questions morphemes of Urdu and to make comparative analysis of Urdu and English languages. There are different types of doublings in English language e.g. adverbs doublings, semantic doubling but question doubling does not exist in English language because it is the unique feature of Urdu language only. Qualitative analysis with purposive sampling approach, with the framework of Lexical Functional grammar (LFG).through the concept of F-Structure from (LFG) theory, double morphemes will be analyzed. For this purpose, data will be collected through document analysis, standard books, articles, published researches, dictionaries and data from common users. 100 sentences, consisting of double morpheme, will be selected and same were put into F-Structure to explore their lexical structure to show the semantic functions in both languages. Simultaneously, the sentences were also analyzed syntactically in order to find out their appropriateness. The study may provide a good level of confidence to develop Urdu National Language processing (UNLP) and enlighten the phenomena that morphological doubling in Urdu used for multiple semantic functions to explore human notions and feelings as compare to any other South Asian Language because Urdu is the only language with per gram. and study will also explore the functional and dynamic aspects of LFG. Keywords: Reduplication, LFG, syntax, Double interrogative morphemes.